Optoelectronic subassemblies having a light-emitting component or a light-detecting component are known. Such sub-assemblies are also referred to as TOSA (Transmitter Optical Sub Assembly) or as ROSA (Receiver Optical Sub Assembly).
Coupling an optoelectronic component of a TOSA or ROSA to an optical fiber to be coupled requires an alignment and fixing of the respective components with extremely high precision in the μm and sub-μm range. This applies particularly when coupling monomode optical fibers. It must be ensured at the same time that during the mounting and in particular during the operation of a subassembly, the optical and electrical coupling locations undergo strain relief, i.e. no forces that might lead to a release or misalignment of the optical coupling or electrical contact-connection act on the optoelectronic component. Such forces may arise in particular as a result of thermal expansion.
DE 199 09 242 A1 discloses an optoelectronic module in which a leadframe with an optoelectronic transducer is positioned in a module housing and encapsulated with a light-transmissive, moldable material. Light is coupled in or out via an optical fiber coupled to a connector of the module housing. The housing is generally formed from metal such that it can absorb thermal stresses that occur.
DE 100 34 865 A1 describes an optoelectronic surface-mountable module in which an optoelectronic component is mounted on a transparent substrate. Substrate and component are arranged in a plastic housing with an optical window. Surface mounting on a printed circuit board can be effected by means of electrical connections led to the outer side of the plastic housing. An optical waveguide is led from the other side of the printed circuit board and coupled to the optoelectronic component via a hole in the printed circuit board. In addition, an imaging optical arrangement is preferably provided between the optical waveguide to be coupled and the optoelectronic component.
DE 102 01 102 A1 discloses a laser apparatus in which a laser diode is mounted by flip-chip mounting on a transparent substrate with an integrated optical lens and emits light into said substrate. The substrate is contact-connected via a leadframe.
It is furthermore known to arrange an optical subassembly in a TO housing. A TO housing has a base plate through which electrical connections are led, and also a metallic cap that is placed onto the base plate. A glass window is soldered in the cap in order to achieve the optical passage. A TO housing is disadvantageously associated with relatively high material costs. What is more, an imaging optical arrangement and a separate coupling unit that is welded onto the TO housing are generally required.
There is a need for cost-effective constructional module techniques which provide a high coupling efficiency for optoelectronic components and at the same time are insensitive to thermal loading.